• Introduction
  • The ČEZ Group and the public »
    • The ČEZ Foundation
    • Projects of the ČEZ Foundation
    • Donations outside the ČEZ Foundation
    • Corporate volunteering
    • Cooperation with Forum of Donors
    • Communication of ČEZ with
      public »
      • Communication with shareholders, investors and analysts
      • Communication with mass media
      • Corporation's media image
      • Communication with the public
  • Environment »
    • Impact of fuel mining and transport on the environment »
      • Mining and transport of classic fuels
      • Clean-up and reclamation of mining areas
      • Nuclear fuel
    • Impact of electric energy production on the environment »
      • Air
      • Water
      • Wastes and spent nuclear fuel
      • Noise
      • Reclamation of the power plants surroundings
      • Renewable resources
    • Impact of transport on the environment and distribution
  • Climate »
    • GHG emissions »
      • Reduction of ČEZ's emissions intensity
      • Preparation of low-emission technologies based on fossil fuels
    • Activities of ČEZ in the field of environmental markets »
      • What are environmental markets
      • Active approach of ČEZ
      • Projects for GHG emissions reduction
    • Energy savings
  • Customers & contractors »
    • Social responsibility of fully integrated companies of the ČEZ Group
    • The ČEZ Group and promotion of electric energy savings
    • Structure of the ČEZ Group –
      ČEZ, a. s., and fully integrated companies »
      • ČEZ Group
      • Foreign acquisitions
  • Our employees »
    • The VIZE 2008 project
    • Corporate culture
    • Staff care
    • Occupational health and safety
    • Relationship with trade unions
    • European Employees Council
 

Water

In the field of water management, the ČEZ Group constantly focuses on the protection of underground and surface waters, potential risk and hazard prevention in relation with the technologies operated. Useful water management is monitored as well. ČEZ obeys the applicable legislation of the Czech Republic and decisions of water management authorities in water management and water protection activities.

The resources of surface water for ČEZ's coal power plants are rivers in the river basin of the Labe, Ohře, Morava and Odra. ČEZ power plants use surface water particularly for cooling purposes and for water treatment for the supply of power and heat engineering boilers. Prior to use, the water should be chemically and mechanically treated to reduce the content of impurities and to ensure conformity for power plant operation. The volume of water used is continuously measured and registered. Quality is checked by qualified laboratories.

ČEZ's power plants use two methods for cooling the condensers. Water consumption is substantially lower for power plants using circulation cooling when compared to flow cooling because only vaporized or discharged water (as sludge or blowdown, i.e. about 5% of the circulating water) is replenished.

The flow cooling technology is used only in Mělník power plant and heat power plant Dvůr Králové on the Labe River and Hodonín power plant on the Morava River, which were constructed on locations with plenty of water for this type of cooling because water consumption is up to ten million m3 per month. The flow cooling water temperature is slightly higher than river water temperature, which is important with respect to the legal requirement to keep river water temperature below 25 ºC after stirring.

Contrary to circulation cooling with vaporization, flow cooling returns water to the river in volumes equal to those input to the power plant. The flow cooling waste water is not contaminated contrary to thickening in cooling towers. The flow cooling is friendlier to the environment but from the economic point of view, the substantially higher volumes of water taken result in circulation cooling being preferred.

Water is supplied to nuclear power plants as well - for Dukovany nuclear power plant, water is taken from the Jihlava River (Mohelno reservoir) and for Temelín nuclear power plant, water is taken from the Vltava River. Water intake for both the nuclear power plants does not exceed the limits specified by the relevant decisions. The limit values of liquid discharges from nuclear power plant are defined in the water management decision issued to the power plant by the relevant water management body while respecting the requirements of the SÚJB. Both the nuclear power plants conform to the limits.

Operation waste waters from coal power plant (oiled waste water, water from chemical treatment, etc.) are purified prior to discharge into rivers according to the state-of-the-art information about water treatment. The volume of waste water discharged is determined by continuous measurement and pollution is monitored by a relevant laboratory.

Scheme of water management of Dětmarovice power plant

Similarly to the atmosphere, the nuclear power plants have a specific regime of discharge into streams when waste liquids of very low radioactive nuclide content are discharged into streams (particularly tricium). Emissions of radioactive nuclides from the nuclear power plants are limited by automated limits determined by SÚJB in approvals on releasing radioactive nuclides into the environment. Adherence to the limits is documented using calculation programmes approved by SÚJB for current radioactive nuclide release into streams under actual hydrological conditions of the year in question. Radioactive nuclide content is carefully monitored and evaluated as well as being monitored independently by a supervisory body (SÚJB); various components of the environment are monitored as well. Similarly to releases of nuclear power plants into the atmosphere, the discharges into streams have negligible effects on the environment and inhabitants as witnessed by the applicable data.

Water management is one of the key technological elements for the operation of coal power plants or nuclear power plants and potential problems related to the operation of water management influence electric power production. One example is the floods in 2003, which substantially influenced not only the operation of hydro power plants on the Vltava River's cascade in relation to the flood wave followed by control of streams, but also the production of some coal power plants.